Interpretation ID: nht71-2.7
DATE: 02/16/71
FROM: AUTHOR UNAVAILABLE; R. A. Diaz; NHTSA
TO: Ford Motor Company
TITLE: FMVSS INTERPRETATION
TEXT: This will acknowledge your letter dated January 22, 1971, to the National Highway Traffic Safety Administration, requesting the addition of the 5 1/2-J alternative rim size for the 175 SR 13 tire size designation to Table I - Appendix A of Federal Motor Vehicle Safety Standard No. 110.
On the basis of the data submitted indicating compliance with the requirements of Federal Motor Vehicle Safety Standards No. 109 and No. 110 and other information submitted in accordance with the procedural guidelines set forth in the Federal Register, Volume 33, No. 195, page 14964, dated October 5, 1963, the 5 1/2-JJ alternative for the 175 a 13 tire size designation will be listed within Table I - Appendix A of Standard No. 110. Our substitution of rim size 5 1/2 J by 5 1/2 JJ follows our practice of not listing the "J" or "JK" rim contours since a footnote to Table I, Appendix "A" states "Where JJ rims are specified in the above table, J and JK rim contours are permissible."
The above change will be published in the Federal Register in the near future.
The addition of new alternative rims to the table is accomplished through an abbreviated procedure consisting of the publication in the Federal Register of the petitioned alternative rim. If no adverse comments are received, the amendment becomes effective after 30 days from date of publication. If comments objecting to amendments are received, additional rule making pursuant to Part 553 of the Procedural Rules for motor vehicle safety standards will be considered.
As we reviewed your attachments we note on attachment I - page 1 a statement that "in compliance with Legal Requirements 4.04 for the U. S. A., the tires were to be burst not only for one wheel position, but for all of the four wheel positions. Federal Motor Vehicle Safety Standard No. 110 - Section 4.4.1 requires that only one tire be tested for retention on the rim under conditions of rapid deflation. There is a possibility of some misunderstanding in these items which may be causing the overseas people doing more testing than necessary.
He also note in attachment III that the(Illegible Words) data is referenced to specific tires but the rim is not identified. This lack of rim identification precludes using the data for petition purposes even though the data level is of interest and shows that a(Illegible Word) seating problem is very unlikely. Fortunately for the purposes of this petition, Attachment II - page 2 contained adequate but less information(Illegible Word) Unseating data.